1. Introduction
Alloy 446 stainless steel sheet, designated by the Unified
Numbering System (UNS) as S44600, is a premium ferritic stainless
steel product renowned for its exceptional resistance to high
temperatures, corrosion, and oxidation. Unlike austenitic stainless
steels (e.g., 304, 316), UNS S44600 is characterized by a high
chromium content (25–27%) and low carbon content, which eliminates
the risk of sensitization (carbide precipitation) during welding or
heat treatment. This sheet product, with a thickness range of
0.4–2.5mm and 2B finishing, balances formability, durability, and
cost-effectiveness, making it a preferred choice for industries
requiring reliable performance in harsh environments—such as
high-temperature processing, chemical exposure, or marine settings.
2. Chemical Composition (Key Parameters)
The chemical composition of UNS S44600 stainless steel is strictly
controlled to ensure its superior properties. Below is the typical
composition per industry standards:
| Element | Content Range (%) | Role |
|---|
| Chromium (Cr) | 25.0 – 27.0 | Enhances oxidation, corrosion, and high-temperature resistance |
| Iron (Fe) | Balance | Base metal providing structural strength |
| Carbon (C) | ≤ 0.10 | Minimizes sensitization and improves weldability |
| Manganese (Mn) | ≤ 1.50 | Improves hot workability without compromising corrosion resistance |
| Silicon (Si) | ≤ 1.00 | Aids in deoxidation during production and boosts high-temp strength |
| Phosphorus (P) | ≤ 0.040 | Controlled to avoid brittleness and maintain ductility |
| Sulfur (S) | ≤ 0.030 | Reduces machinability slightly but preserves corrosion performance |
| Nitrogen (N) | ≤ 0.040 | Enhances tensile strength without significant impact on formability |
3. Mechanical & Physical Properties
3.1 Mechanical Properties (for 2B Finished Sheets, Thickness
0.4–2.5mm)
| Property | Standard Value | Test Condition |
|---|
| Tensile Strength (σb) | ≥ 515 MPa (75 ksi) | Room temperature, annealed |
| Yield Strength (σ0.2) | ≥ 275 MPa (40 ksi) | Room temperature, annealed |
| Elongation (in 50mm) | ≥ 20% | Room temperature, annealed |
| Hardness (Brinell) | ≤ 183 HB | Annealed state |
| Hardness (Rockwell B) | ≤ 88 HRB | Annealed state |
3.2 Physical Properties
| Property | Value |
|---|
| Density | 7.7 g/cm³ (0.278 lb/in³) |
| Melting Point Range | 1427 – 1455 °C (2600 – 2650 °F) |
| Thermal Conductivity | 25 W/(m·K) at 20 °C (68 °F) |
| Coefficient of Thermal Expansion (20–100 °C) | 10.8 × 10⁻⁶/°C (6.0 × 10⁻⁶/°F) |
| Electrical Resistivity | 0.6 Ω·mm²/m at 20 °C (68 °F) |
4. Product Specifications
This UNS S44600 stainless steel sheet is manufactured to strict
dimensional and finishing standards, with the following key
specifications:
| Specification Item | Details |
|---|
| Thickness Range | 0.4 mm – 2.5 mm (tolerance: ±0.02 mm for thickness <1.0 mm;
±0.03 mm for thickness ≥1.0 mm) |
| Width | Customizable, common ranges: 1000 mm, 1219 mm, 1500 mm (max width:
2000 mm) |
| Length | Customizable, common ranges: 2000 mm, 2438 mm, 3000 mm (max length:
6000 mm) |
| Surface Finishing | 2B Finish: Cold-rolled, heat-treated, pickled, and skin-passed.
Features a smooth, matte, and uniform surface—ideal for
applications requiring moderate aesthetics and easy cleaning. |
| Flatness | ≤ 1 mm/m (meets ASTM flatness standards for thin-gauge stainless
steel sheets) |
| Cutting Options | Standard: Slit coils or cut-to-size sheets; Custom: Laser cutting,
plasma cutting, or shearing (per customer request) |
5. Manufacturing & Quality Standards
To ensure consistency and performance, the UNS S44600 stainless
steel sheet complies with global industry standards:
| Standard Category | Relevant Standards |
|---|
| Chemical Composition | ASTM A240/A240M, ASME SA-240, EN 10088-2 |
| Mechanical Properties | ASTM A240/A240M, ISO 3506-1 |
| Dimensional Tolerances | ASTM A480/A480M (for thickness, width, and length), EN 10058 |
| Surface Finish (2B) | ASTM A480/A480M, EN 10088-2 (Designation: 1D + 2B) |
| Weldability | AWS D1.6 (stainless steel welding standard) |
| Quality Control | ISO 9001:2015 (quality management system), ISO 14001 (environmental
management) |
6. Key Features
UNS S44600 stainless steel sheets (0.4–2.5mm, 2B finish) stand out
for the following advantages:
- Exceptional High-Temperature Resistance: Sustains strength and
oxidation resistance up to 815 °C (1500 °F), making it suitable for
high-heat applications (e.g., furnace parts, heat exchangers).
- Superior Corrosion Resistance: High chromium content provides
resistance to general corrosion, pitting, and crevice corrosion in
mild acids, alkalis, and marine environments (outperforms 430
ferritic stainless steel).
- No Sensitization Risk: Low carbon content prevents carbide
precipitation at grain boundaries during welding, eliminating
intergranular corrosion.
- Good Formability: The 0.4–2.5mm thin gauge and 2B finish enable
easy bending, rolling, and stamping—ideal for fabricating complex
components.
- Cost-Effective: Lower nickel content (compared to austenitic grades
like 316) reduces material costs while maintaining reliable
performance.
- Smooth 2B Surface: The matte, uniform finish is non-reflective,
easy to clean, and compatible with post-processing (e.g., painting,
coating).
7. Applications
Thanks to its balanced properties, this UNS S44600 stainless steel
sheet is widely used across industries:
- High-Temperature Processing: Furnace liners, heat exchanger tubes,
boiler components, and kiln parts.
- Chemical & Petrochemical: Storage tanks for mild acids (e.g.,
sulfuric acid, nitric acid), chemical processing equipment, and
pipe cladding.
- Marine & Coastal: Boat hulls, coastal architectural trim, and
offshore platform components (resists saltwater corrosion).
- Automotive: Exhaust systems, catalytic converter housings, and
underbody components (withstands high heat and road salt).
- Appliances: Oven interiors, grills, and heat-resistant panels for
kitchen appliances.
- Construction: Decorative trim for industrial buildings, HVAC
ductwork, and fire-rated components.
8. Packaging & Shipping
To protect the sheet’s 2B finish and prevent damage during transit,
the following packaging measures are implemented:
- Individual Sheet Protection: Each sheet is wrapped in a PE
(polyethylene) film to resist moisture, dust, and scratches.
- Stack Packaging: Sheets are stacked on a plywood pallet (or steel
pallet for heavy loads) and secured with steel straps to prevent
shifting.
- Moisture Barrier: For sea shipping or humid environments, the
entire pallet is covered with a kraft paper + aluminum foil
composite bag to block moisture and corrosion.
- Labeling: Each package is labeled with product details (UNS S44600,
thickness, size, finish), batch number, and handling instructions
(e.g., “Keep Dry,” “Handle with Care”).
- Shipping Options: Available via sea freight (for bulk orders), air
freight (for urgent orders), or land transport (for regional
deliveries). Custom packaging (e.g., wooden crates) is available
upon request
439 Stainless Steel Sheet 2B 2D Finishing 0.8-3.0mm TISCO POSCO
